<!doctype html>
<html lang="en-US">
  <head>
    <style>
      :root {
        --brand-blue: #0063cc;
      }

      a:where(:any-link) {
        color: var(--brand-blue);
        font-weight: bold;
      }

      .button {
        display: inline-block;
        padding: 0.5rem;
        color: white;
        background-color: var(--brand-blue);
        font-weight: normal;
        text-decoration: none;
      }
    </style>
  </head>
  <body>
    <p><a href="#">normal link</a></p>
    <p><a href="#" class="button">Button link</a></p>
  </body>
</html>
